Stefanie Powers and a horse with the same color hair
The coloring is really a secondary issue. The important point is that the popular Hart to Hart star is wearing a diaphanous top which renders her virtually topless. These pictures must be at least 30 years old, yet I can't recall ever seeing them before. Sorry, but I don't know the original source, or whether they are completely genuine and unmodified.
For comparison, she did do one topless scene in her movie career, in a 1970 stinker called Crescendo. (IMDb page)
From the comment section:
"Wow, and that was pretty late in life. Check the hands and arms. I'd guess 50s or very late 40s."